P1430: EPIDEMIOLOGY AND TREATMENT OF SICKLE CELL DISEASE ASSOCIATED VASO-OCCLUSIVE CRISES IN INPATIENT AND EMERGENCY CARE SETTINGS: A SYSTEMATIC LITERATURE REVIEW AND META-ANALYSIS
Authors: Ami Patel, Monica Neri, Wilco Jacobs
Journal: HemaSphere (2023)

Topic: 26. Sickle cell disease Background: Vaso-occlusive crises (VOCs) are the leading cause of hospitalization for patients with sickle cell disease (SCD) and treatment options are limited to supportive care. Despite posing a significant burden on patients and the healthcare system, the clinical course of VOCs treated in an inpatient or emergency care setting has not been synthesized across patient populations. Aims: To characterize the epidemiology of SCD-related VOCs in adult patients treated in inpatient and emergency care settings, a systematic literature review with meta-analysis was performed. Methods: Medline, EMBASE and Clinicaltrials.gov were searched from January 1, 2012 to October 11, 2022. Two reviewers independently selected references in duplicate, reaching consensus and using a referee if needed. Studies were included if they comprised >25 patients hospitalized or seen at an emergency department (ED) for SCD with VOC, ≥18 years of age and/or treated in adult facilities. Extracted outcomes were demographics, medical history, treatment, clinical course including length of stay (LoS), complications and readmission rates (defined for inpatient encounters as an admission following discharge and for ED encounters as a subsequent ED visit). Meta-analyses using random effects models of means and proportions were performed in STATA, using inverse variance weights. Missing variance was imputed from available estimates in other studies and heterogeneity was assessed with I2. Results: This review included 74 studies with 97 study groups and 931,194 observations (reported as either patients with at least one VOC event or VOC events). Study populations were predominately from the US (81%), followed by Europe (9.3%). Most study groups were from the ED (50%), followed by inpatient setting (43%), while the remainder were seen in both settings of care. The crude age range was 16 to 68 years overall. The weighted mean age was 32.6 years for ED patients and 31.2 years for inpatients, while the proportion of males was 48% and 43% respectively. Use of analgesics, including opioids, was frequently reported. For ED patients (22 study groups), median time to initiation of opioids or analgesia ranged from 60 minutes to 4.5 hours (mean 18.6 to 190 minutes). Acute chest syndrome (ACS) was the most frequent incident SCD-related complication, with 11% of observations presenting with ACS (95% CI 8% to 14%) in 23 study groups reporting these data. LoS in the ED showed a weighted mean of 5.3 (95% CI 4.7 to 6.0) hours (9 study groups), while inpatient weighted mean LoS was 6.7 (95% CI 6.4 to 7.1) days (28 study groups) (see Figure). Proportions of readmissions within 30 days from discharge were available for 49 study groups. The weighted mean proportion of observations with 30-d readmission for all causes/unspecified was 30% (95% CI 28% to 32%), for SCD was 28% (95% CI 23% to 33%), and for VOC 34% (95% CI 24% to 45%). Summary/Conclusion: This is the first systematic literature review synthesizing data on SCD VOC treated in inpatient and emergency care settings. Although there was heterogeneity in the study populations and results, the healthcare burden of these VOCs remains high as demonstrated by variability in reported time to analgesia initiation, long LoS, and high 30-d readmission rates. An unmet need exists to treat SCD-related VOCs.Keywords: Vasoocclusive crisis, Sickle cell disease